Expandable metallic stent placement in the tracheobronchial tree in dogs

Expandable metallic stents (Gianturco zig-zag wire stents) of various sizes were placed in the trachea of eight dogs to establish conditions suitable for endotracheal wire stent placement. Stents of 3.0 cm in diameter and 2, 3, or 4 cm in length were constructed with 0.018, 0.016, or 0.013 inch stainless steel wire. Optimal dilatation of the trachea was attained with stents 2 cm long made of 0.013 and 0.016 inch wire, and their surface became covered with ciliated columnar epithelium. In contrast, stents with stronger expansive force, such as those 2 cm long made of 0.018 inch wire, became deeply embedded in the membranous portion of the trachea. With stents of little expansive force, such as those 3 or 4 cm long, dilatation of the trachea was inadequate regardless of the caliber of the wire, and consequently these stents were not completely covered with epithelium. The results of the study suggest the therapeutic potential of expandable metallic stents for clinical treatment of patients with tracheobronchial stenosis.